2 1 8 FRESH-WATEE ALO^ PROM BURMA.
Si. et/aihoid«s Josh. (Burmese Desm. 1886, p. 642, t. 23, figs. 22, 23) may
related to Sl. proteotum by roasou of tiie ionn of tbe vertioal view, but ifc is desHtute of' the
bidenticulate wfirts, Aud tbe front view is vGry di^erent in sb&pe>
143. STAURASTfiDM SUBGEMMÜLATUM W. & G. S. West. Alg. Madag. 1895, p. 76
t. 8, f. 34.
Var. GKACiLius W. & G. S. West, 1. c. t. 8, f. 35.
Forma minor, cum annulis duobus granulorum circa processus imumquemque.
Long. 26-5/i; lat. cuiii proc. 29-31/i.
flai.—Maiisang, near Hsipaw (No. 24193).
144. Staurasteum hexacurüii (Ehrenb.) Wittr. Gotl. Ol. Söt7. Alg. 1872, p. 51.
Desmidmm h'.xauei'os Ehrenb., 1838.
Staurastrum trìaorne (lìréb.) Mcnogb. Synops. Desm. 1840, p. 225; Ralfs,
Brit. Desm. 1848, p. 134, t. 22, f. 11; t. 34, f. 8a.
S'aS.—Momauk, east of Bbamo (No. 21551).
145. Staurastedm oalodermum sp. n. (PI. xv, fig. 26).
St. parvum, eirciter tani loagum quam latum, leviter constrictum; semicollulffi
Bcudiformes, basì inflata cum seriebus transversis tribus granulorum, aagulia in
processuB breves crassos productis, annulis 4 granulorum circa processus unumquemque,
•annulo ad basin e granulis geminatis formatis, apieibus processuum tridenticulatis
apice semicellulce leviter convexo et granulato; a vertice vi?aj quadrangulares (cum
processibus cruciform es), angulis in processus crassos attenuates productis, lateribus
valde concavis, processibus cum nnnulis granulorum ornatis (annulo ad basin processuum
e granulis geminatis formatis), cum annnlo granulorum geniinatorum 8 in centro.
Long. 26/i; lat. (cum proc.) 26-32'6/i; lat. isthm. 9-5/x.
i^ai.—Mansang, near Hsipaw (No. 24193).
Tlie only species approaohing Sl. oalodermum is Sl. basidentatum Borge (Cblor. Norska Finmark
1892, p. 8, t. 1, f. 5), but tbe former is disfcinguisbed by tbe inBafced base of the semioells by
the deeply concave median part of tbe sides of tbe vertical vie-57, and by tbe ring of geminate
granules at tbe apices of tbe semicella.
146. Staurastrum capitellatum sp. n. (PL xv, fig. 29).
St. parvum, circiter I f p l o latius quato longum (cum processibus), leviter constrictum
; semicelluliE subtrapeziformos, marginibus infenoribus concavis et leviter undulatis,
apice convexo et verrucoso (verrucis bidenticulatis circifer 4 visis), angulis
Buperioribus in processus breves crassos subcapitatos productis, apieibus processuum cum
denticulis minutis circ. 10 (visis 6), trans basin semiseilularum cum seriebus duobus
granulorum miuutorum ; a vertice vi8a2 quadrangulares, latoribus concavis, angulis in
processus crassos subcapitatos productis, verruca bidenticulata supra basin processuum
utrobique et verruca emarginata nuinuta intra basin processuum instructce
Long. 29^; lat. 26-33/^; lat. iatlim. 9.
Eah.—Mansang, near Hsipaw (No. 24193).
Tbis species stands nearest to 8t. ceylanicum W. &.. Q. S. West, with wbiob it should be
compared.
STAURASIRÜM. 219
147. Staurastrum monticux^osiposme sp. n. (PI. xv, fig. 33).
St. parvum, paullo latius quam longum (cum processibus) profundissime constrictura,
sinu aperto acuminato ad apicem; semicellulas subellipticse, margine inferiori
valde ventricoso, margine superiori convexo, angulis in processus breves et crassos horizontaliter
dispositos productis, cum annulis circ. 3 granulorum circum processus unumquemque,
apieibus processuum tridenticulatis, verrueis conicis duobus (distantibus) infra marginem
apicaleni semicellularam ; a vertice vis£e rhomboideo-ellipticse, polis in processus
breves et crassos productis, verrucis conicis binis infra basin processus uniuscujusque.
Long. 27/4 ; Int. cum proc. 32/^; lat. isthm. ; crass.
Mansang, near Hsipaw (No. 24193).
In tbe general outline of tbe front view tliis species closely resembles Si. polymorphum Bréb.,
but it is at once disfcinguisbed from that species by tbe rliomboidal character oí the vertical view,
and by the four conical warts at the apex of eaob semicell.
From Si. oxyacanihnm Arch. var. bicm-m Lund. (Desm. Suec. 1871, p. 67) ifc diSers in its
, smaller size, its shorter horizontally-disposed processes, which ore neither dentate-crenate at the
margin nor bifurcate afc the apices, and in the conical apical warts in place of spines.
It should also be compared with Sl. monikulosum Bréb. var. rkomboidium Boldt (Siber.
Chloropby, 1885, p. 119, t, 6, f. 38), from which it differs in its longer processes, which are
granulate and tridenticulate at tbe apices. The conical warts do not project above the apex of the
semioells of SI. moniicuhùform$, whereas ths oorresponding. dentate projections of Sl. moniiculo&uM,
always stand out prominently.
148. Staurastrum tetraceeum Ralfs, 1845 ; Brit. Desm, 1848, p. 137, t. 23,
f. 7.
Var. TRIGRANULATUM Vai". n. (Pi. XV, fig. 19).
Semxcellulai cum processibus paullo brevioribus et validioribus, a vertice vis®
lateribus trigranulatis.
Long, sine proc. 10>t ; cum proc. 19-21/^ ; lat. sine proc. 7-5-8'5/i, cum proc.
22-24^; lat. isthm. 4-2/^; crass. 5-8-6/^.
—Mansang, near Hsipaw (No. 24193).
Tbis variety differs from Si. tctracerum iialfs var. undu!aiim W. & G. S. West (Alg. Madag.,
1895, p. 80, t. 9, f. Gj in the proportionately longer body of the semicelle, and in tbe three median granules
on each side of tbe vertical view. It somewhat resembles Si. irregukre W. & G. S. "West. (New Brit.
Freshw. Alg 1894, p. 12, t. 2, f. 49, 50), but the basal part of the semicella is too rounded and the
central wart is absent.
149. Staurastrum g í r a t u j i sp. n. (PI. xv, fig. 37).
St. minutum, 2i-plo latius quam longum (cum processibus), modice constrictum;
semicellulffi subtnangulares, lateribus et apice leviter convexis, angulis superioribus in
processus longos tenuissimos horizontaliter dispositos subiter productis, marginibus
processuum delicatissime serrato-crenulat», apieibus processuum minutissime tridenticulatis;
a vertice visas triangulares, lateribus leviter convexis, angulis in processus
longos rectos productis, processibus oblique dispositis o ángulo unoquoque ; membrana
glabra.
Long. 12m; lat. sine proc. 9-5/i, cum proc. 27-5-28-5m ; lat. isthm.
Z/ai.-Mansang, near Hsipaw (No. 34193).